help with weird noise!

[vande97]

well i have a knocking noise going on in the motor, it is NOT a tick tick noise either, it is more of a knock knock knock noise, it sounds like is coming right from the upper intake or atleast that is where i can here it the most, and i can hear it right around tappet covers, it is really weird, after the motor warms up it quiets down a little but you can still here it, expecially inside the car. I just cant figure it out. the motor only has about 1500 miles on it , i can only really here it good when it is at lower rpm. and ideas would be great!

thanks,

P.S if it was a bent rod wouldnt the motor shake like a BITC*??
mine is not shaking tho!

[exgmguy]

Maybe a loose rocker arm??

[vande97]

I checked the rockers and seem to be fine

[exgmguy]

It is hard to guess on a noise, but if your oil pressure is good then that would eliminate any lower end problems. Maybe you have a bent valve??

Have you checked compression?

[7DMACH1]

Sound like maybe a piston on wrist pin.

[PKRWUD]

A little info on bottom end engine noises:


Main Bearing Knock:
Main bearing knock is usually apparent when the engine is pulling hard, when an engine is started, during acceleration, or at speeds above 35 mph.

Loose Flywheel or Broken Flexplate:
A loose flywheel or broken flexplate can usually be detected by this procedure:
1) Advance engine idle to 2000 rpm.
2) Turn off the ignition switch.
3) When the engine has almost stopped, turn the switch on again.
4) Repeat this procedure several times.
5) If the flywheel is loose or the flexplate is broken, a distinct knock will be heard every time the ignition switch is turned back on.

Harmonic Balancer:
A separated harmonic balancer will generally produce a heavy rattling noise that can be heard at low speed.

Rod Knock:
Excessive connecting rod bearing clearance noises are usually a light rap or clatter much less in intensity than main bearing knocks and the loudest when the engine is "floating" or running with a light load at from 25 to 35 mph. The noise will become louder as engine speed is increased. By grounding out each of the spark plugs, one at a time, you can determine from which cylinder the noise is coming. The noise may not be eliminated entirely by grounding, but it will be reduced considerably in intensity. The easiest way to ground out the cylinders is by inserting a 1.5" piece of 5/32" vacuum hose on each terminal on the distributor cap, and then placing the spark plug wires over the vacuum hose. With the alligator clip end of a non-powered 12 volt test lamp attached to ground, touch the test light tip to the vacuum hose to ground out that cylinder.

Piston Slap:
Piston slap is loudest when the engine is cold, and lessens or disappears after the engine is warm. When driving the car (at from 25 to 30 mph) the noise will increase in intensity as the throttle is opened and additional load is applied. To detect piston slap, try the following procedure:
1) Pour several ounces of 40 weight engine oil into the suspected cylinder(s).
2) Crank the engine for several revolutions with the ignition turned off. This will allow for the oil to work itself down past the rings and act as a cushion.
3) Install the spark plug(s).
4) Start the engine.
5) If the noise is eliminated, the engine has a piston slap condition.

Piston Pin Noises:
Piston pin noise is usually the result of excessive piston pin clearance. This will cause a sharp, metallic, double-knock sound most noticable when the engine is idling. Sometimes the noise is more audible at car speeds of from 25 to 35 mph. To test for excessive piston pin clearance noise, use this procedure:
1) Run the engine at idle speed.
2) Retard the spark to reduce the intensity of the knock.
3) Return the spark timing to the normal setting.
4) Short out each spark plug, one at a time. The double-knock sound will become more audible at the cylinder with the loose pin.

Other possibilities for you to consider include:
1) Loose timing chain hitting the inside of the front cover.
2) Connecting rod bolts hitting the inside of a dented oil pan.

I'm not saying your noise is coming from the bottom end, but at least now you have the info necessary to determine for sure.

Take care,
-Chris

[vande97]

first of all i would like to say THANKS to PKRWUD, thanks for taking the time to let me know the diff symtoms of a noise, also thanks to the other guys that put in some info also it is very appreciated!, well i will try the diffrent test,s to see what is going on , it sounds the loudest when i first start the car and then when it warms up it goes away a little bit but still there, it is louder when i put the car under a load from a start, the oil pressure is perfect!!!!, i tighten down the rockers another half turn but it did not help any, could the rockers be to tight ? would that make a nocking sounD?, once i get about over 2000rpm and have my foot to the floor it goes away and i can not here it , the car does not seem to have lost any power, but i can not deal with this noise anymore. it is killing me that i dont know what is going on!!!

thanks again everyone

[vande97]

hey PKRWUD, well the noise seems to becoming from the driverside of the car, i really can here it good when car is cold, it sounds like it is coming from the tappet cover and intake area, I still can not figure it out, I can get under the car and not here it as well so it does not sound like it is coming from the the crank or oil pan area. the car does not shake and it runs great other then that it is not doen on power at all, smokes alittle bit but i think that is due to fule pressure being way out of wack, the plugs look ok tho, hmm i still dont know anymore thought would be of help!!

thanks again man